Study Shows Why Beer Mats Do Not Fly in a Straight Line — University Of Bonn

upstart writes:

Study Shows Why Beer Mats Do Not Fly In A Straight Line - University Of Bonn:

Anyone who has ever failed to throw a [circular] beer mat into a hat should take note: physicists at the University of Bonn have discovered why this task is so difficult. However, their study also suggests how to significantly increase accuracy and range.

[...] Physicists at the Helmholtz Institute of Radiation and Nuclear Physics and the Argelander Institute for Astronomy at the University of Bonn have now investigated this question. According to them, the behavior of the beer mat is inevitable, at least when employing the usual throwing technique: it unavoidably begins to drift off after 0.45 seconds at most. Playing cards go awry after just 0.24 seconds, CDs after 0.8 seconds.

The reason for this is the interaction between gravity, lift, and the conservation of angular momentum: the mat tips backwards shortly after being thrown due to gravity. This gives it an angle of attack, similar to a landing aircraft. This angle creates lift in the airflow. However, the lifting force is not applied in the center of the mat, but rather in the front third," explains PhD student Johann Ostmeyer, who came up with the idea for the study.

Read more of this story at SoylentNews.